For the first 4 listed, I'm reasonably sure I've got the ratios correct (which means I've been able to confirm from multiple sources). However for Snowpeak I've seen different ratios claimed, and I can't find any info on the Jetboil canisters. Anybody know these ratios definitively?

Anybody care to share what their experiences are with regards to the lowest temps that they have used various brands of canisters down to (and still gotten good results)? I'm looking for inverted use especially. Thanks!

I've got no info to offer, but do have a question: theoretically/practically, what ratio would go down to the lowest temps? I'm not familiar enough with the effect of different blends to know what a best ratio might be. But I'd love to see the results of this thread as winter rolls in and I'm still using a canister stove for most of my trips.

Tim,Since propane boils at a lower temperature, the more propane there is in the mix, the better cold weather performance. However I believe that propane also requires more pressure and thus needs a more heavy duty canister which is why 100% propane comes in thick steel canister (think Coleman here). I may have that wrong...

Isobutane boils lower than N-butane so it would seem the best mix would be Isobutane and propane. What the optimum is I don't know. Coleman Powermax seems to be the best fuel but those only fit the Coleman Xpert and Xtreme stoves (now out of production).

Well I can tell you that the fuel ratio varies in different parts of the world. Here in Euroland, we haveColeman - 70%, 0%, 30%Primus - 50%, 25%, 25%

Here is a graph I made which shows the boiling point (C) of 3 different mixtures (Coleman and Primus as above, and a hypothetical 20% propane, 80% i-butane) when the canister is used UPRIGHT. This shows how the boiling point rises as the propane is used up first. Remember, boiling point is the temp at which the total vapour pressure matches sea-level atmospheric pressure; the canister needs to be at least 5C above the boiling point for there to be sufficient pressure to operate the stove.

When the canister is used INVERTED, the propane/butane mix does not change and so the boiling point remains constant at the value on the temp axis. In this case, all three mixtures are almost identical!

Actually, as far as I can see, the fuel mixes sold by the different companies vary from year to year and country to country. Most confusing. Anyhow, the limiting factor is the pressure inside the canister at 50 C (DOT regulations). Some examples are as follows..

This needs some explanation of course. First of all, the compositions shown here may have changed over the years. Second, the pressures are absolute, and you will only get gas out while the pressure exceeds 1 atmosphere - the dashed line. Third, what's currently available in America may differ from what is available in Australia.

The pure propane has too much pressure for the conventional screw-thread canister. But Coleman do sell a stronger steel canister with a different fitting. If you want to go pulking at -40 C, that's the way to go.

The Kovea 70% isobutane / 30% propane curve overlays the Powermax 60% butane 40% propane curve. These were the best performing brands available in Australia at the time. Both are pushing the pressure limit for the canisters.

Your graph shows more mixtures than mine, but it is still reassuring to find some common data points:Both graphs show the boiling point of 70/30 Coleman and MSR 80/20 IsoPro to be close to -25CThe boiling point stays more or less constant if the canister is used inverted (you know that :-) my graph attempts to explain what happens when the canister is used upright. It took a bit of effort with a spreadsheet to work this out.

This premium fuel, an 80/20 blend of isobutane and propane, boosts the performance of canister stoves. It outperforms standard butane/propane mixtures and burns clean to reduce soot and clogs.

Improved Performance: 80/20 blend of isobutane and propane delivers superior performance throughout the life of the canister and in colder temperatures.Clean-Burning: Optimal fuel blend results in reduced soot and clogs.Recyclable: Canisters can be recycled. Consult your local recycling center for regulations.Made in Korea

>> Anybody care to share what their experiences are with regards to the lowest temps that they have used various brands of canisters down to (and still gotten good results)? I'm looking for inverted use especially. Thanks!

My son and I just took a two day trip where temps in the evening and morning were a steady 35F. We were using a Snowpeak Litemax stove with a MSR pancake canister and a Snowpeak gold mini. The MSR failed everytime after about 90 secs. The only way I could get it to perform was to wrap it in a fleece and put it in my foot box during sleep each night. The Snowpeak worked everytime we whipped it out.

I could have gotten a bum MSR canister, but that was our experience with the two at 2500ft, 35F, and using a Litemax.

Actually the Snowpeak was older than the MSR. I'm going to do some testing on my deck this week. I have another MSR canister to use with the other two and try to find out what was up with the situation.

I wonder if it could be down to differences in the dimensions of the canister fitting - the flange and the Lindal valve, such that in the case of the MSR canister the pin on the stove is not fully opening the Lindal valve.

This can also happen with the MSR Pocket Rocket when that big rubber washer goes hard in the cold.